1-(omega-aroylalkyl)-4-alkyl-1, 2, 3, 6-tetrahydropyridines



r 3,030,372 Patented Ap 17, 1952 3,030,372 1-(w-AROYLALKYL)-4-ALKYL-1,2,3,6-TETRA- HYDROPYRIDINES Paul A. J. Janssen, Vosselaar, near Turnhout, Belgium,

assignor to Research Laboratorium Dr. C. Janssen I N.V., Beerse, Belgium, a company of Belgium No Drawing. Filed Aug. 25, 1960, Ser. No. 51,793 12 Claims. (Cl. 260-297) The present invention relates to' compounds of the formula ll Y-C-Alk-N 2 wherein Y is phenyl, fluorophenyl, methoxyphenyl and dimethoxyphenyl; Alk is alkylene, and Z is alkyl. Among the alkylene radicals represented by Alk, especially lower alkylene radicals are preferred, for example, methylene, ethylene, propylene, trimethylene, methylpropylene, tetramethylene, dimethylpropylene, hexamethylene, and the like. Among the alkyl radicals represented by Z, especially lower alkyl radicals are preferred, for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, tert-pentyl, neopentyl, hexyl, isohexyl, heptyl, octyl, and homologous monovalent hydrocarbon aggregates embracive of fewer than 9 carbon atoms arranged in chains, either straight or branched.

Equivalent to the foregoing compounds for purposes of the present invention are non-toxic acid addition salts thereof,the composition of which is depicted by the formula wherein Y, Alk and Z have the meanings hereinbefore assigned; A is one equivalent of an anion-for example, chloride, bromide, iodide, nitrate, phosphate, sulfate, sulfamate, methyl sulfate, ethyl sulfate, benzenesulfonate, toluenesulfonate, acetate, lactate, succinate, malate, maleate, tartarate, citrate, gluconate, ascorbate, benzoate, cinnamate, or the like-which in combination with the cationic portion of a salt aforesaid, is neither pharmacologically nor otherwise undesirable in physiological dosage.

The compounds to which this invention relates are useful because of their valuable pharmacological properties. Thus, for example, they possess analgesic, mydriatic, hypnotic, and barbiturate potentiating activity.

The subject compounds are prepared by condensation of an w-haloalkyl aryl ketone with a 4-alky1-1,2,3,6-tetrahydropyridine Those embodiments of the present invention which possess two carbon atoms joining the carbonyl and nitrogen functions are also prepared by a Mannich reaction involving an aryl methyl ketone, a 4-alkyl-1,2,3,6-tetrahydropyridine and formaldehyde 0 Y-iflCHl (CHgOh-I- HN Z Conversion oftthe amine bases of this invention to cor-responding acid addition salts is accomplished by simple admixture of these compounds with one equivalent of any of various inorganic and strong organic acids, the anionic portion of which conforms to A as hereinabove defined.

The following examples describe in detail certain of the compounds illustrative of the present invention, and methods which have been devised for their manufacture. However, the invention is not to be construed as limited thereby, either in spirit or in scope, since it Will be apparent to those skilled in the art of organic synthesis that many modifications, both of materials and methods, may be practiced without departing from the purpose and intent of this disclosure. In the examples hereinafter detailed, temperatures are given in degrees centigrade, pressures in pound per square inch, and relative amounts of materials in parts by weight, except as otherwise noted.

Example 1 J-(Z-benzoylethyl)-4-ethyl 1,2,3,6 tetrahydr pyridine hydrochl0riae. A mixture of 48 parts of acetophenone, 18 parts of paraformaldehyde, 47 parts of 4-ethyl-l,2,3,6- tetrahydropyridine, 400 parts of isopropyl alcohol and 400 parts of concentrated hydrochloric acid is heated under reflux for 1 hour. At the end of this time an additional 12 parts of paraformaldehyde is added, and the resultant mixture is heated under reflux for 1 hour, and then allowed to stand at room temperatures overnight. The mixture thus obtained is evaporated to dryness, and the residue is taken up in 360 parts of acetone; the acetone solution is filtered, and the filtrate is chilled. The precipitate thus obtained is removed by filtration, washed with acetone, and dried in air to yield crude, crystalline 1-(2-benzoylethyl)-4-ethyl-1,2,3,6-tetrahydropyridine hydrochloride. Recrystallization of the crude product from 640 parts of isopropyl alcohol affords the pure product as white crystalline platelets, melting at about 174175. The structure may be expressed as -o omom-Uomomncr Example 2 O 7 ll F-QGGHlGEuN -o H2CHs.HOl

Example 3 I-[Z-(Z-fluorobenzoyl) ethyl] 4 ethyl-I,2,3,6-tetrahydropyridine hydr0chl0ride.Substitution of 55 parts of ofluoroacetophenone for the acetophenone of Example 1 gives, by the procedure therein detailed, 1-[2-(2-fluorobenzoyl) ethyl] 4 ethyl-1,2,3,6-tetrahydropyridine. The structure may be expressed as Example 4 1-[2-(4-meth0xybenz0yl) ethyl] 4 ethyl-1,2,3,6-tetrahydropyridine hydrochloride.Substitution of 60 parts of p-methoxyacetophenone for the acetophenone of Example 1 gives, by the procedure therein detailed, 1-[2-(4-methoxybenzoyl) ethyl] 4 ethyl-1,2,3,6-tetrahydropyridine hydrochloride, melting at 162-164. The structure may be expressed as II omoQ-o on ombpjomomnoi Example 1-[2-(2-methoxybenzoyl) ethyl] 4 ethyl-1,2,3,6-tetrahydropyridine hydrochloride.--Substitution of 60 parts of o-methoxyacetophenone for the acetophenone of Example 1 gives, by the procedure therein detailed, 1-[2-(2-n1ethoxybenzoyl)ethyl-] 4 ethyl-1,2,3,6-tetrahydropyridine hydrochloride. The structure may be expressed as 0 ll Q4: omom CHzCHsI-[Cl Example 6 1-(3-benzoylpr0pyl) 4 ethyl-1,2,3,6-tetrahydr0pyridine hydrochloride.A mixture of 91 parts of 'y-chlorobutyrophenone, 112 parts of 4-ethy1-1,2,3,6-tetrahydropyridine and 1200 parts of anhydrous toluene is heated in a sealed tube at 110 for 48 hours. At the end of this time the reaction mixture is cooled to room temperatures, and the resultant precipitate is removed by ,filtration. The filtrate is extracted with water, the aqueous solution thus obtained is extracted with ether, and the resultant ether layer is combined with the original toluene solution. The organic solution is dried over anhydrous potassium carbonate, and then filtered. Hydrogen chloride gas is passed through the filtrate, the resultant precipitate is removed by filtration, and the filtrate thus obtained is evaporated to dryness to yield a residue which is combined with the previously removed precipitate. The combined solid material is taken up in 800 parts of acetone and 1000 parts of isopropyl alcohol, and the solution thus obtained is filtered. The filtrate is allowed to stand at room temperatures for 3 hours, whereupon precipitation occurs; the precipitate is removed by filtration, washed with acetone, and dried in air to yield 1-(3- benzoylpropyl) 4 ethyl-1,2,3,6-tetrahydropyridine hydrochloride, melting at about 199;-200. The filtrate is cooled to obtain a second crop, melting at 188-490". The structure may be expressed as ll Q0 ongomomN omomnoi Example 7 1-(4-benz0ylbutyl) 4 ethyl-1,2,3,6-zetrahydr0pyridine hydrochloride.Substitution of 97 parts of A-chlorovalerophenone for the 'y-chlorobutyrophenone of Example 6, and adoption of reactions conditions of 120 for 40 hours in place of the values for these variables in the cited example yields, by the procedure therein detailed, 1-(4-benzoylbutyl) 4 ethyl-1,2,3,6-tetrahydropyridine hydrochloride, melting at about 157-.15 8. The structure may be expressed as 0 ll Q-oomomomomQomomnor Example 8 1-[3-(4-fla0robenzoyl)propyl] 4 ethyl-1,2,3,6-tetrahydropyridine hydrochloride.-Substitution of 100 parts of 'y-chloro-p-fiuorobutyrophenone for the 'y-chlorobutyrophenone of Example 6, and adoption of reaction conditions of 120 for 40 hours in place of the values for these variables in the cited example yields, by the procedure therein detailed, 1-[3:.(4-fiuorobenzoyl)propyl,- 4 -.ethy1- 1,2,3,6-tetrahydropyridine hydrochloride, melting at 188- 190. The structure may be expressed as 0 ll F-Q-G omomomN omomnoi Example 9 1-[3-(Z-fluorobenzoyDpropyl] 4 ethyl-1,2,3,6-tetrahydropyridine hydrochloride.Substitution of parts of 'y-chloro-oefluorobutyrophenone for the 'y-chlorobutyrophenone of Example 6, gives, by the procedure therein detailed, 1-[3-(2-fluorobenzoyl)propyl] 4 ethyl-l,2,3,6- tetrahydropyridine hydrochloride. The structure may be expressed as i -o CHzCHrOHzOCHzCHa.HO1

Example 10 ll cmoQ-ccmomonzUomomHm Example 11 1- [3-(2-meth0xybenz0yl)propyl] -4-ethyl 1,2,3,6-tetra.- hydropyridine hydrochl0ride.-Substitution of parts of 'y-chloro-o-methoxybutyrophenone for the 'y-chlorobutyrophenone of Example 6 gives, by the procedure therein detailed, 1 [3 (2 methoxybenzoyhpropyl] 4- ethyl 1,2,3,6 tetrahydropyridine hydrochloride. The structure may be expressed as ll -o omomomOomomnm Example 12 I-(Z-benzoylethyl)-4-pr0pyl 1,2,3,6 tetrahy'dropyridine hydrochloride-e-A mixture of 43 parts of B-chloropropiophenone, 63 parts of 4-propyl-1,2,3,6-tetrahydropyridine and 1000 parts of anhydrous toluene is heated in a sealed tube at 100 for 2 hours; a precipitate is formed after about 15. minutes. The reaction mixture thusob'tained is cooled to room temperatures, Water and ether are added, and the resultant layered mixture is shaken; the organic layer is dried over anhydrous potassium carbonate. Hydrogen chloride gas is passed through the dried organic layer, and the resultant precipitate is removed by filtration, and taken up in 800 parts of hot acetone. The acetone solution is filtered, and then allowed to stand for 2 hours at room temperatures. The resultant precipitate is removed by filtration; the crude 1-(2-benzoylethyl)-4-propyl 1,2,3,6 tetrahydropyridine hydrochloride thus obtained melts at about 161162, The filtrate is cooled to obtain a second crop melting at. 157-160. The structure may be expressed as ll Q40 omom -ornomom.no1

Example 13 1-(3-benz0ylpr0pyl) -4-propyl 1,2,3,6 tetrahyclropyridine hydrochl0ride.Sl1bstitl1ti0n of 47' parts of 'ychlorobutyrophenone for the p-chloropropiophenone of Example 12, and adoption of reaction conditions of 145. for 40 hours in place of the values for these variables in the cited example gives, by the procedure therein detailed, l-(3-benzoylpropyl)-4-propyl 1,2,3,6 tetrahydropyridine hydrochloride, melting at 176178. The structure may be expressed as Q-iioruomomUomomomnol Example 14 1-(4-benz0ylbutyl)-4-pr0pyl 1,2,3,6 tetrahydropyri- I dine hydrochl0ride.Substitution of 49 parts of A-chlorovalerophenone for the fl-chloropropiophenone of Example 12, and adoption of reaction conditions of 140 for 40 hours in place of the values for these variables in the cited example gives, by the procedure therein detailed, 1-(4-benzoylbutyl)-4-propyl 1,2,3,6 tetrahydropyridine hydrochloride, melting at about 153-154". The structure may be expressed as l o Q-li omcmongolmijcnzomomnoi Example 1-[2-(4-flu0r0benz0yl)ethyl]-4-pr0pyl 1,2,3,6 tetrahydropyridine hydroch[wide-Substitution of 48 parts of 8-chloro-p-fluoropropiophenone for the 8-chloropropiophenonefof Example 12 gives, by the procedure therein detailed, 1-[2-( 4-fiuorobenzoyl) ethyl] 4 propyl-1,2,3,6- tetrahydropyridine hydrochloride, melting at about 178- 179. The structure may be expressed as Example 16 I-[Z-(Z-fluorobenzoyl) ethyl]-4-pr0pyl 1,2,3,6 tetrahydropyridine hydrochl0ride.--Substitution of 48 parts of ,B-chloro-o-fiuoropropiophenone for the fi-chloropropiophenone of Example 12 gives, by the procedure therein detailed, 1-[2-(2-fluorobenzoyl)ethyl] 4 propyl1,2,3,6- tetrahydropyridine hydrochloride. The structure may be expressed as i oomonnQ-omcmomnm Example 17 1-[3-(4-fluor0benzoyl)pr0pyl] -4-propyl 1,2,3,6 tetrahydropyria'ine hydrochl0ride. Substitution of 50 parts of -chloro-p-fiuorobutyrophenone for the ,B-chloropropiophenone of Example 12, and adoption of reaction conditions of 125 for 45 hours in place of the values for these' variables in the cited example gives, by the procedure therein detailed, 1-[3-(4-fluorobenzoyl)propyl]-4-propy1- 1,2,3,6-tetrahydropyridine hydrochloride, melting at about 184-185". The structure may be expressed as Example 1 8 1-[3-(Z-fluorobenzoyl)propyl] -4-pr0pyl-1,2,3,6 tetrahydropyridine hydrochl0ride.Substitution of 50 parts of 'y-chloro-o-fluorobutyrophenone for the B-chloro-propiophenone of Example 12 gives, by the procedure therein detailed l [3 (2-fluorobenzoyl)propyl]-4-propyl- 1,2,3,6-tetrahydropyridine hydrochloride. The structure may be expressed as i Q CCH2CH2CHgN CHzCH1CHa.HCl

6 Example 19 1-[2-(4-meth0xybenz0yl)ethyl]-4-propyl-1,2,3,6 tetrahydropyridine hydrochloride.-Substitution of 50 parts of fi-chloro-p-methoxypropiophenone for the fl-chloropropiophenone in Example 12 gives, by the procedure therein detailed, 1-[2-(4-methoxybenzoyl)ethyl]-4-propyl-l,2,3,6-tetrahydropyridine hydrochloride, melting at 163-165". The structure may be expressed as Example 20 1-[2-(2-meth0xybenz0yl)ethyl]-4-pr0pyl-1,2,3,6 tetrahydropyridine hydr0chl0ride.Substitution of 50 parts of fi-chloro-o-methoxypropiophenone for the B-chloropropiophenone of Example 12 gives, by the procedure therein detailed, 1- [2-(2-methoxybenzoyl)ethyl]-4-propyl-1,2,3,6-tetrahydropyridine hydrochloride. The structure may be expressed as i ooH2oH2@oH2oHtoH3.Ho1

Example 21 ll omo-Q-o ornamental: CH2CH2CHILHC1 Example 22 I [3 (2 -methoxybenzoyDpropyl]-4-pr0pyl-1,2,3,6- tetrahydropyridine hydrochloride-Substitution of 53 parts of *y-chloro-o-methoxybutyrophenone" for the chloropropiophenone of Example 12 gives, by the procedure therein detailed, 1-[3-(2 methoxybenzoyl)propyl]-4-propyl-1,2,3,6 tetrahydropyridine hydrochloride. The structure may be expressed as CHsO 0 Q-c omomoHzN CHgCHzCH JHJl Example 23 1-[3(3,4-dimelhoxybenzoyl)propyl]-4-propyl 1,2,3,6- tetrahydropyridine hydrochloride.-Substitution of 61 parts of 'y-chloro-3,4-dimethoxybutyrophenone for the fi-chloropropropiophenone of Example 12, and adoption of reaction conditions of 140 for 65 hours in place of the values of these variables in the cited example gives, by the procedure therein detailed, 1-[3-(3,4-dimethoxybenzoyl)propyl] -4-propyl-1,2,3,6-tetrahydropyridine hydrochloride, melting at about 144145. The structure may be expressed as 0 ll QC CHzCH OHgN CH2CHzCH .HCl

Example 24 I-[3-(2,4 dimethoxybenzoyDpropyl] -4-ethyl 1,23,6- tetrahydropyridine oxalate-A mixture of 61 parts of 'y-chloro-2,4-dimethoxybutyrophenone, 56 parts of 4- ethyl-1,2,3,6-tetrahydropyridine and 1200 parts of anhydrous toluene is heated in a sealed tube at for 40 hours. The reaction mixture is cooled to room temperatures, and extracted with water; the aqueous phase is back-extracted with ether, and the ethereal layer is added to the toluene solution. The organic solution thus obtained is dried over anhydrous potassium carbonate, and filtered; the filtrate is evaporated to dryness, and the residue is taken up in 800 parts of ethanol. To the resultant solution is added 32 parts of oxalic acid dihydra-te, the solvents are removed by evaporation, and the oily residue which remains is taken up in 1200 parts of acetone. The resultant acetone solution is cooled to for 48 hours, and the precipitate which results is removed by filtration to give 1-[3-(2,4-dirnethoxybenzoyl)propyl]-4- ethyl-l,2,3,6-tetrahydropyridine oxalate. The crude salt is dissolved with heating in 1200 parts of acetone and 400 parts of isopropyl alcohol; the solution thus obtained is allowed to cool to room temperature, whereuponprecipitation occurs. The pure salt is removed by filtration, and melts at 138-140". The structure may be expressed i Q OH3OC CHzCHzCHzN CHzCHa. (00011 Example 25 1-[3-(3,4-dimethoxybenzoyl)propylI-l-ethyl 1,25,6- tetrahydropyridine 0xalate.Substitution of 61 parts of 'y-chloro-3,4-dimethoxybutyrophenone for the 'y-chloro- 2,4-dirnethoxybutyrophenone of Example 24 gives, by the procedure therein detailed, 1-[3-(3,4-dimethoxybenzoyl)propyl]-4-ethyl-l,2,3,6 tetrahydropyridine oxalate, melting at 136-140. The structure may be expressed it Q @-o CHQCHrCHaN omomxooon CHaO Example 26' OGHQCHQCHSN CHrCHzCHs-(COOH):

8 What is claimed is: 1. A compound of the formula 0 ll Y-O-(Iower alkylene)-N -(lower alkyl) wherein Y is a member of the class consisting of phenyl, mono-fluorophenyl, mono-methoxyphenyl and di-methoxyphenyl.

10 2. A compound of the formula 0 Q-iJ-(lower alkylenej -N (lower alkyl) 8. 1. [2 (4-fluorobenzoyUethyl]-4-propyl-l,2,3,6- tetrahydropyridine.

9. A compound of the formula 0 H i @C-(lower a1kylene)- (lower alkyl) 10. 1 [3-(4-methoxybenzoyl)propyl]-4-ethy1-1,2,3,6- tetrahydropyridine.

11. A compound of the formula 0 I] i @O-(lower a1kylene)-N (lower alkyl) 45 12. 1 [3-(3,4-dimethoxybenzoyl)propyl]-4-propyl- 1,2,3,6-tetrahydropyridine.

CHaO

40 euro CH O References Cited in the file of this patent UNITED STATES PATENTS Janssen Feb. 28, 1961 OTHER REFERENCES Lutz et al.: Chem. Absts., vol. 42, column 1224 (1948). 

1. A COMPOUND OF THE FORMULA 